The invention relates to an electronic balance with a measured value receiver, a digital signal processing unit, a display unit and a calibrating device controlled by the digital signal processing unit for placing on and lifting off a calibrating weight by means of a motor.
Balances of this type are known e.g. from EP 0 93 183 (B1). This publication suggests that in order to assure a correction calibration, the result of a calibrating cycle be subjected to a plausibility test and that the balance be freed only upon a positive result of this test. It indicates as an example of a plausibility test that the calibrating cycle be performed repeatedly and that the results be checked for uniformity. In such circumstances, no data is furnished about the number of repetitions. However, the exact uniformity of two calibrating cycles can only be assured in the case of balances with a low and average resolution. Another disadvantage is the fact that the balance is no longer freed upon a negative outcome of the plausibility test, that is, no more weighings are possible.
The calculating of the average value and the standard deviation from several weighing results is also generally known (e.g. DE-OS 23 20 612).
The invention therefore has the problem of indicating an electronic balance of the initially mentioned type in which a reliable and exact calibration is possible, even in the case of a high resolution, in which the time required for the calibration is reduced to the minimum necessary and false calibrations are nevertheless largely excluded and which can be flexibly adapted to various customer requests and ambient conditions.